Rocker arm for internal-combustion engines



Sept. 12, 1950 J. R. WINTER, JR

ROCKER ARM FOR INTERNAL-COMBUSTION ENGINES Var/2,

Filed Nov. 21, 1949 Pmmed Sept. 12, 1950 ROCKER ARM FOR INTERNAL-COMBUSTION ENGINES John R. Winter, Jr., Detroit Mich, assignor'to John R. Winter, Sr., Detroit, Mich.

Application November 21, 1919, Serial No. 128,621

4 Claims. (01. 74-519) The present invention relates to improvements in the construction of rocker arms for internal combustion engines of the overhead valve type.

The primary object of the invention is to provide improved means for controlling the feeding of lubricating oil to the valve tappet end of such rocker arms.

It is the usual practice in present-day overhead valve engines to supply lubricating oil under pressure through a longitudinal bore in the rocker arm shaft, communicating radial ports in the shaft being provided inside the hub of each rocker arm to deliver the oil to oil channels in the arm, the channels formed in the arm being designed to conduct metered quantities of oil to opposite ends of the arm. Great difllculty is encountered in the proper metered feeding of oil to the valve ends of such rocker arms because of the fact that if too. much oil finds its way to the valve end of an arm and comes into engagement with the valve stem, increased oil consumption is apt to occur, particularly in worn engines, because of the tendency to draw oil into the cylinder along the valve stem, between the stem and its guide, on each suction stroke. In my previously flledapplication Serial No. 78,217, filed February 24, 1949, I have disclosed an arrangement wherein oil is conducted upwardly through a generally vertical riser hole in the rocker arm, and then allowed to flow to the ends of the arm through open-topped channels, a novel metering clip being provided over, the open upper end of the riser hole to prevent upward squirting of oil from such hole, and also to meter the quantity of oil which is allowed to flow into the opentopped channels for conduction to the ends of the arm. With the aid of such metering clips, very accurate control of the quantity of oil delivered to the top channels is provided and decreased oil consumption without'sacrifice of satisfactory lubrication can be obtained. The oil metering and control clip disclosed in such prior application is adapted for use with several previously known types of rocker arms having groove-like oil channels extending along their tops. Insofar as I am aware, all such top oil channels heretofore em-v ployed have been of uniform cross section throughout their length. I have found that with such previously known types of rocker arms, although the installation of the clip device greatly improves the accuracy of 'oil control and reduces oil consumption for the reasons indicated, a new limiting factor, preventing the attainment 'ofthe utmost efliciency appears, even with the aid of 'such clips, at high engine speeds.

' With such clips, the oil flow to the valve end of the arm can be reduced to the absolute minimum which will assure satisfactory lubrication, but at high engine speeds, there is a tendency of the oil to build up or "pile up" on top of the arm, and flow over the side of the arm, rather than flowing smoothly and continuously along the oil channel to the outer end of the arm.

It is also an object of the present invention, therefore, to overcome the difllculty just outlined, and to provide a simple, inexpensive, and reliable rocker arm construction adapted for use with an oil metering and control clip of the indicated variety, the arrangement being such that the clip may be designed to reduce the oil flow to the valve end of the arm to the absolute minimum required for satisfactory lubrication, the arm itself being so designed that, even at high speeds. oil will not flow from the top oil channel over the side of the arm. The invention attains this objective by graduated contouring of the top oil channel which leads to the valve end of the arm. the cross-sectional area of such channel being increased progressively toward the valve end of the arm.

Other objects and advantages of the invention will become apparent upon consideration of the I present disclosure in its entirety.

In the drawing:

Figure 1 is a side elevational view of a rocker arm incorporating the principles of the present invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a central vertical sectional view taken substantially on the line 3-3 of Fig. 2 and looking in the direction of the arrows; and

Figs. 4, 5 and 6 are cross-sectional views taken substantially on the lines 4-4, 5--5 and 6-6, re-

spectively, of Fig; 1, and looking in the direction of the arrows. g d p The general construction and arrangement of I the'principal parts of the rocker arm may correspond to those or the rocke arms disclosed in my previously filed copending applications Serial Nos. 701,150 nowp'atented and 78,217. The body of the arm is blanked andjformed from a single piece of sheet metal, shaped andfolded' to provide two laminae l5 l6 whichlie against'one another. The laminae are secured together by an integral part 10 at the push pin end, such part I!) being wrapped around'the stem l2 of the push pin element. The laminae l5 and l6-'are"also secured together by welding, as at. the points designated l1, l8 and i9." Aligned hub receiving openings as were formed in intermediate widened portions of the laminae, and such openings are aligned when the laminae are folded together. A tubular sheet metal hub 22 is projected through the hub opening thus formed and the hub is bulged as indicated at 24 and 23 on opposite sides of the arm laminae to secure the hub and arm portions together and additionally hold the laminations against separation. A hearing sleeve 23 is fitted in the hub 22.

In the formation of the bulged portions 24, 23, the metal which is bent outwardly from the surface of the hub to define each bulge is curved about a small radius in such manner as to leave annular internal, generally V-shaped grooves 23, 33. The inner faces of the grooves 23, 33 are closed by the bearing sleeve 23 so that the grooves form annular internal channels extending interiorly of the hub assembly and completely therearound.

The bearing sleeve 23 is provided on its inner face with an internal groove 32 and communicating radial holes 33, 34 adapted to communicate with a radial oil feed port (not shown) in the rocker arm shaft. In registry with one of the holes as 33, a slot 35 is formed in the hub 22 extending in an axial direction entirely through the hub wall and long enough to provide communication between the hole 33 and the internal channel 33 in the hub. A similar axial slot 33 is formed in the hub in registry with the aperture 33 in the bearing sleeve and of such length as to provide communication between aperture 34 and internal oil channel 23. A longer axial slot 33 is formed in the hub 22 in registry with the oil riser passage 43 and connecting such passage with both of the channels 23, 33. Oil supplied to the holes 33, 33 from the shaft, therefore, must travel through the slots 35, 33 to the internal channels 33, 23, respectively, and then around the channels 33 and 23 to passage 33 before such oil can pass upwardly through the riser passage 43 to the top of the arm.

Oil discharged through the riser is conducted lengthwise over channels formed in the top surface of the arm to the end bearing pads, but the amount of oil which can reach such top passages is restricted by special metering means including the damming and metering ears 43 and 33 and the oil control and metering clip, generally designated 42. Clip 42 is fitted over the arm in such manner that a top baffling portion 44 thereof is located spacedly above the open top of the riser passage 43, to intercept any oil which tends to squirt from such passage, and divergent, downwardly inclined, deflecting guide portions 43 of the clip are adapted to guide excess oil angularly downwardly and away from the top of the arm. A metered quantity of oil finds its way longitudinally of the arm through a pair of V-shaped channels as 43 defined by the somewhat divergent upstanding ears 43, 33. The ears are integrally formed and angularly bent from the material of the laminae of the arm sections. An area between the two pairs of upstanding cars is formed as a notch-like depression 32 in the top of the arm and defines a predetermined laterally open space above the riser passage 43 and beneath the baiiie portion 44, such space being open at the sides beneath the deflecting guides 43 to allow excess oil to escape at the sides.

Due to the relatively high surface tension and viscosity of the oil, the space 52 tends to remain substantially full of oil, and a part of such oil finds its way longitudinally between the cars 48, 53 and travels along the top edges of the laminae to the ends of the arm. As explained in my previously filed applications referred to, substantially V-shaped channels of shallow form may be provided along the top edge of the arm simply by folding the blank in the proper direction. This forms a natural V due to the fact that some drawing of the metal occurs during the shearing thereof in the blanking operation, so that one edge of each lamina oi the folded blank will be somewhat higher than the other, the higher edge being placed at the outside by the act of folding the two sections about their end portion M. In the absence of special treatment, this would provide a shallow channel of substantially uniform cross section extending outwardly to the ends of the arm. In the present construction, such channels are of nonuniform cross section, however, as will appear.

The ends of the clip 42 are bent downwardly to provide terminal edges 34, 33 which lie closely adjacent the tops of the arm and coact with the ears 43, 33 and with the channels in the top of the arm to limit in a positive manner-the volume of oil which can pass between such ears and out from under the ends of the clip into the top channels. If the spacing between the ears and the proportions of the clip structure 42 are properly engineered, it will be appreciated that the amount of oil allowed to pass outwardly under the clip edge 34 toward the valve end of the arm can be accurately metered and held at a proper value.

Where the top channel leading toward the valve end is of uniform cross section, as in the arms of the prior art, the operation is entirely satisfactory at low engine speeds, and a very substantial improvement is obtained at all engine speeds. including high speeds, but I have found that at high engine speeds the reciprocation of the arm is so rapid that the smooth flow of oil along the top channel to the valve and is interfered with. At high speeds the oil tends to pile up in the channel, and a substantial quantity of it will flow out of the top channel leading to the valve end and over the sides of the arm approximately in the region designated 33. Some of such oil will run outwardly along the sides of the arm toward the head of the push pin.

In accordance with the present invention, I provide a top oil channel 33 which is of graduatedly increased width and depth as it extends outwardly from the cars 33 to the valve end of the arm. Such tapered slot may be formed by contouring the edges of the laminae before folding them together, and although such groove is shown as of straight-sided V cross section and uniformly tapered form, it will be appreciated that this specific contouring is subject to variation. The increased depth and width of the slot toward the outer end compensates for the resistance of the oil to proper outward flow which develops at high speeds and retains the oil in the channel without permitting it to flow over the side,so that it may be fed in the intended manner downwardly through the passage 32 to the pad surface of the head portion l4 of the valve bearing element or push pin l2, where it may perform its lubricating operation without escaping over the side of the arm.

Due to the tendency of the graduated oil channel to retain the oil against such escape over the sides of the arm at high speeds, it is possible to reduce the spacing between the metering cars 33 to the minimum, so that no excess oil, not actually needed for lubricating the push pin bearing of engine eillciency.

It will be understood that although the disclosed metering means for preventing delivery of an excess volume of oil to the top channel 69. comprises the clip structure 42 and the coacting.

damming ears 50, different metering means could be employed without detracting from the value of the graduated top channel 60, which will perform its operation regardless of variations of the metering means. For example, a diiferent type of metering means is disclosed in Patent No. 2,288,831, which is intended to allow a relatively large and controlled quantity of oil to escape over the sides of the arm close to the riser hole. The specific metering means disclosed herein, however. is my preferred mode of attaining the metering action in conjunction with the graduated feeding channel means 80.

While it will be apparent that the preferred embodiment of the invention herein disclosed is well calculated to fulfill the objects above stated. it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subioined claims.

What is claimed is: Y

1. A rocker arm construction for internal combustion engines, including a hub portion and an arm, and a bearing element carried by the arm defining an open-topped channel extending longitudinally along the upper edge of the arm outer end of said'arm, an oil riser passage-despaced above the upper end of the riser passage and a metering part restricting the delivery of oil from the riser passage to the channel. 7

2. A rocker arm construction for internal combustion engines, including a hub portion and an arm, and a bearing element carried by the outer end of said arm, an oil riser passage-defining portion extending upwardly from the hub portion to the. top offthe arm, portions of said ..tions having a bailiing part extending over but to provide communication between said riser passage and said bearing element, said channeldeflning portions being formed of substantially fiat and straight walls arranged in V-form and which diverge from one another to graduatedly increase the cross-sectional area of the channel toward said outer end of the arm which carries said bearing element.

3. A rocker arm construction for internal combustion engines, including a hub portion and an arm, and a bearing element carried by the outer end of said arm, an oil riser passage-defining portion extending upwardly from the hub portion to the top of the arm. portions of S811! arm defining an open-topped channel extending longitudinally along the upper edge of the arm to provide communication between said riser passage and said bearing element, said channel having outwardly diverging wall portions imparting to said channel a graduatedly increased cross-sectional area toward said outer end of the arm which carries said bearing element.

4. A rocker arm construction for internal combustion engines, including a hub portion and an arm, and a bearing element carried by the outer end of said arm, an oil riser passage-defining portion extending upwardly from the hub portion to the top of the arm, portions of said arm defining an open-topped channel extending longitudinally along the upper edge of the arm to provide communication between said riser passage and said bearing element, said channel having outwardly diverging wall portions imparting to said channel a graduatedly increased cross-sectional area toward said outer end of the arm which carries said bearing element, and metering means restricting the rate of oil delivery from the riser passage to the channel.

JOHN R. WHTI'ER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,278,195 Noack Sept. 19. 1918 1,699,659 Fagan Jan. 22, 1929 1,822,546 Sperry Sept. 8. 1981 1,871,623 Le Fevre Aug. 16, 1932 2,288,831 O'Harrow July I, 1942 2,415,213 Leake I ieb. 4, 194'! 2,457,948 Vincent Jan. 4, 1949 

